Ann Thorac Surg 2007;84:280-282
© 2007 The Society of Thoracic Surgeons
Case Reports
Mycotic Coronary Artery Aneurysm From Fungal Prosthetic Valve Endocarditis
Wing Yeen, MBBS, MBAa,
Antonio Panza, MDa,
Stephen Cook, MDb,
Christopher Warrell, BSa,
Benjamin Sun, MDa,
Juan A. Crestanello, MDa,*
a Division of Cardiothoracic Surgery, The Ohio State University Medical Center, Columbus, Ohio
b Division of Cardiology, The Ohio State University Medical Center, Columbus, Ohio
Accepted for publication February 2, 2007.
* Address correspondence to Dr Crestanello, Division of Cardiothoracic Surgery, The Ohio State University, 8th Floor North Doan Hall, 410 W 10th Ave, Columbus, OH 43210 (Email: juan.crestanello{at}osumc.edu).
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Abstract
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Two cases of mycotic aneurysms of the left anterior descending coronary artery in patients with fungal prosthetic valve endocarditis are reported. One was managed with exclusion and interposition graft, and the other was managed by aneurysm excision, wide debridement, and distal bypass. The current literature and management strategies are reviewed.
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Introduction
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Mycotic aneurysms of the coronary artery are rare [1]. Their management is controversial. Some authors advocate excision and distal bypass, whereas others recommend an interposition graft [2]. We report 2 patients with mycotic aneurysms of the left anterior descending coronary artery associated with fungal prosthetic valve endocarditis. Their presentation, surgical management, and review of the literature are discussed.
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Case Reports
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Patient 1
A 38-year-old man with previous mechanical aortic and mitral valve replacement presented with fever, chills, hypotension, and Candida glabrata fungemia. Echocardiogram revealed large vegetations on the mitral and aortic prosthesis limiting leaflet motion and causing severe stenosis of both valves. Cardiac catheterization revealed a discrete aneurysm in the mid left anterior descending coronary artery (LAD) (Fig 1A). His electrocardiogram was normal. There were no wall motion abnormalities.
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Fig 1. Patient 1: (A) Preoperative coronary angiogram showing left anterior descending coronary artery (LAD) aneurysm (arrow). (B) Intraoperative picture showing the proximal (*) and distal LAD (**), the saphenous vein interposition graft already sutured to the proximal LAD, and the mouth of the aneurysm. (C) Completed interposition graph showing the proximal (*) and distal LAD (**).
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The patient underwent reoperation with re-replacement of his mitral and aortic prosthetic valves. There was a 1 cm saccular aneurysm at the middle third of the LAD. The walls of the aneurysm were thinned, but free of mural thrombosis, vegetations, or inflammation. The LAD was longitudinally opened over the aneurysm with extension of the arteriotomy for 1.5 cm proximally and distally where the artery was normal. A short segment of reversed saphenous vein graft was anastomosed as an interposition graft between the proximal and distal ends of the artery (Figs 1B, 1C). The patient’s recover was uneventful. Postoperative coronary magnetic angiogram demonstrated patency of the interposition vein graft (Fig 2).
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Fig 2. Patient 1: A three-dimensional coronary magnetic resonance angiogram demonstrating patency of the interposition graft between the proximal and distal left anterior descending coronary artery (arrow).
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Patient 2
A 27-year-old man with native aortic valve Candida parapsilosis endocarditis presented with an anterior wall myocardial infarction, secondary to a septic embolus to the LAD (Fig 3A). The LAD was opened with two stents and the aortic valve was replaced. Six months later the patient had recurrent fevers and fungemia develop. An echocardiogram demonstrated prosthetic aortic valve endocarditis and aortic root abscess. A coronary angiography showed in-stent stenosis and an aneurysm at the junction of the two stents (Fig 3B).
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Fig 3. Patient 2: (A) Embolic occlusion of the left anterior descending coronary artery (LAD) (arrow). (B) Preoperative coronary angiogram showing the LAD in-stent stenosis (hollow arrow) and aneurysm (solid arrow). (C) Intraoperative picture showing the debrided segment of the LAD with a probe in the proximal (*) and distal LAD lumen (**).
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At surgery, an aortic root replacement was performed with an aortic homograft. The tissues surrounding the LAD stents were heavily inflammed. A 10-mm aneurysm with soft whitish walls was present at the junction of the two stents. A 3-cm segment of the mid LAD coronary artery, including the stents and the arterial wall, was excised and debrided (Fig 3C). The proximal end of the LAD was ligated. The left internal mammary artery was anastomosed in an end-to-end fashion to the distal LAD. The postoperative course was uneventful.
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Comment
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Aneurysms of the coronary arteries are rare [1]. Their incidence ranges from 1.5% in autopsy series to 4.9% in angiography series [1]. Atherosclerotic aneurysms account for 50% of cases in adults, followed by Kawasaki’s disease, congenital aneurysm, arteritis, infectious, lymphadenopathy, trauma, congenital dysplasia, and cocaine abuse [1]. The most common site for coronary aneurysms is the right coronary artery followed by the left anterior descending and circumflex arteries [3].
The term "mycotic," coined by Sir William Osler, is used to identify aneurysms secondary to an infectious cause [4]. However it does not imply a specific fungal cause. Mycotic aneurysms are usually associated with infective endocarditis. They can also be seen in patients with sepsis. Coronary mycotic aneurysms are seen in less that 0.5% of all patients with infective endocarditis [1]. Their incidence may be underestimated because coronary angiography is not routinely performed in patients with endocarditis.
Because of their rarity, the microbiology of mycotic coronary artery aneurysms is not well established. Staphylococcus aureus and Streptococcus viridians endocarditis account for the majority of reported cases in which identification is made [5]. Salmonella and pseudomonas have also been reported [6, 7]. The authors are not aware of any previously published cases of mycotic coronary aneurysms associated with fungal endocarditis.
Mycotic aneurysms are caused by: (1) direct colonization of the coronary arteries, (2) medial injury from immune complex, and (3) sterile infarction of the vasa vasorum. Direct colonization can occur by emboli to the vasa vasorum or by direct luminal invasion of the arterial wall [8]. Although in the first case the mycotic lesion might have resulted from any of these mechanisms, in the second case the stent placement on an infected embolus could have caused intimal disruption and direct invasion of the fungi into the coronary wall. The natural history of coronary mycotic aneurysms is not well defined. Small aneurysms may resolve with antibiotic therapy, whereas aneurysms greater than 1 or 2 cm in diameter may enlarge and eventually rupture. Arterial thrombosis and distal embolization have also been reported [9].
The management of mycotic coronary aneurysms is different from the one of atherosclerotic lesions. Atherosclerotic aneurysms may be managed expectantly unless they are large, at high risk of rupture, or have shown predisposition for thrombosis or distal embolization [8]. Mycotic coronary aneurysms can be treated with antibiotics if they are small and if no associated cardiac surgical interventions are needed. Otherwise the aneurysms should be excised or excluded from the circulation and the distal coronary artery should be revascularized [8]. Revascularization can be achieved by an interposition graft or by distal bypass [8]. In presence of acute inflammation or infection, distal bypass may be a better alternative to avoid laying a graft in an infected field. If the aneurysm is distal in the arterial bed, with a small territory at risk, ligation alone may be performed.
The exclusion of the aneurysm with an interposition vein graft was an appropriate option for our first patient who had no evidence of active inflammation or infection in the arterial bed or in the surrounding tissues. In the second patient, the presence of infected stents and significant peri-arterial inflammation required arterial resection and extensive debridement. A distal bypass to the healthy left anterior descending coronary artery using the internal mammary artery was chosen to avoid the infected field.
In conclusion, mycotic coronary artery aneurysms are rare. Their incidence may be underestimated because not all patients with endocarditis are subjected to coronary angiography. When diagnosed, an aggressive surgical approach is advised to avoid rupture, thrombosis, or distal embolization.
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References
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- Syed M, Lesch M. Coronary artery aneurysm: a review Prog Cardiovasc Dis 1997;40:77-84.[Medline]
- Kalangos A, Julia PL, Ozler A, Jebara VA, Fabiani J, Sezerman O. Successful surgical treatment of a coronary artery mycotic aneurysm Ann Thorac Surg 1994;58:1521-1523.[Abstract]
- Maehara A, Mintz GS, Ahmed JM, et al. An intravascular ultrasound classification of angiographic coronary artery aneurysm Amer J of Card 2001;88:365-370.
- Osler W. Gulstonian lectures on malignant endocarditis BMJ 1885;1:467-470.[Free Full Text]
- Berkowitz JM, Lansman S, Fyfe B. Coronary artery mycotic aneurysm following endocarditis of a composite aortic graft: a case report and literature review Angiology 1998;49:145-150.[Medline]
- Howe HS, Wong JS, Ding ZP, et al. Mycotic aneurysm of a coronary artery in SLE—a rare complication of salmonella infection Lupus 1997;6:404-407.[Abstract/Free Full Text]
- Leroy O, Martin E, Prat A, et al. Fatal infection of coronary stent implantation Cathet Cardiovasc Diagn 1996;39:168-170.[Medline]
- Love K. Infective endocarditis of the aortic valveIn: Emery RW, Aron KV, editors. The aortic valve. Philadelphia, PA: Hanley & Belfus; 1991. pp. 269-281.
- Durak DT. Infective and noninfective endocarditisIn: Hurst JW, editor. The heart, arteries and veins. New York, NY: McGraw-Hill; 1990. pp. 1130-1157.
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Abstract
Introduction
